Question: If $x \oplus y = 4x^{2}-y^{2}$ and $x \diamond y = (5-x)(y)$, find $5 \oplus (-5 \diamond -1)$.
Explanation: First, find $-5 \diamond -1$ $ -5 \diamond -1 = (5-(-5))(-1)$ $ \hphantom{-5 \diamond -1} = -10$ Now, find $5 \oplus -10$ $ 5 \oplus -10 = 4(5^{2})-(-10)^{2}$ $ \hphantom{5 \oplus -10} = 0$.